|Scientific Name:||Ziphius cavirostris|
|Species Authority:||G. Cuvier, 1823|
|Infra-specific Taxa Assessed:|
|Taxonomic Notes:||Recent genetic analysis confirmed that this genus is monotypic (Dalebout et al. 2005).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.|
|Reviewer(s):||Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)|
Global trend or abundance data for this species are unavailable but abundance is at least 100,000. This species also has a very large range. As with other beaked whales, threats that could cause widespread declines include high levels of anthropogenic sound, especially military sonar and seismic surveys, and bycatch. The combination of the large global range and relatively high abundance with possible declines driven by more localized threats is believed sufficient to rule out a 30% global reduction over three generations (criterion A).
|Range Description:||Cuvier's beaked whales may have the most extensive range of any beaked whale species (Heyning 1989, 2002). They are widely distributed in offshore waters of all oceans, from the tropics to the polar regions in both hemispheres. Their range covers most marine waters of the world, with the exception of shallow water areas, and very high-latitude polar regions. They are found in many enclosed seas, such as the Gulf of California, Gulf of Mexico, Caribbean Sea, Sea of Japan, and the Sea of Okhotsk (but not in the Baltic or Black Seas). This is the only species of beaked whale regularly found in the Mediterranean Sea (Podesta et al. 2006).|
Native:Albania; American Samoa (American Samoa); Anguilla; Antigua and Barbuda; Argentina; Aruba; Australia; Bahamas; Bangladesh; Barbados; Belize; Benin; Bermuda; Bonaire, Sint Eustatius and Saba (Saba, Sint Eustatius); Brazil; Brunei Darussalam; Cambodia; Cameroon; Canada; Cape Verde; Cayman Islands; Chile; China; Cocos (Keeling) Islands; Colombia; Comoros; Congo; Congo, The Democratic Republic of the; Cook Islands; Costa Rica; Côte d'Ivoire; Croatia; Cuba; Curaçao; Denmark; Djibouti; Dominica; Dominican Republic; Ecuador; El Salvador; Equatorial Guinea; Falkland Islands (Malvinas); Faroe Islands; Fiji; France; French Guiana; French Polynesia; Gabon; Gambia; Germany; Ghana; Gibraltar; Greece; Grenada; Guadeloupe; Guam; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; India; Indonesia; Iran, Islamic Republic of; Ireland; Italy; Jamaica; Japan; Kenya; Kiribati; Korea, Republic of; Kuwait; Liberia; Madagascar; Malaysia; Maldives; Marshall Islands; Martinique; Mauritania; Mexico; Micronesia, Federated States of ; Monaco; Morocco; Mozambique; Myanmar; Namibia; Nauru; Netherlands; New Caledonia; New Zealand; Nicaragua; Nigeria; Niue; Northern Mariana Islands; Norway; Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines; Pitcairn; Portugal; Puerto Rico; Russian Federation; Saint Helena, Ascension and Tristan da Cunha; Saint Kitts and Nevis; Saint Lucia; Saint Martin (French part); Saint Pierre and Miquelon; Saint Vincent and the Grenadines; Samoa; Senegal; Seychelles; Sierra Leone; Singapore; Sint Maarten (Dutch part); Solomon Islands; Somalia; South Africa; Spain; Sri Lanka; Sudan; Suriname; Sweden; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Togo; Tonga; Trinidad and Tobago; United Kingdom; United States; Uruguay; Vanuatu; Venezuela, Bolivarian Republic of; Viet Nam; Virgin Islands, British; Virgin Islands, U.S.; Wallis and Futuna; Western Sahara; Yemen
|FAO Marine Fishing Areas:||
Atlantic – western central; Atlantic – northeast; Atlantic – eastern central; Atlantic – southwest; Atlantic – southeast; Atlantic – northwest; Indian Ocean – western; Indian Ocean – eastern; Mediterranean and Black Sea; Pacific – southeast; Pacific – northeast; Pacific – northwest; Pacific – eastern central; Pacific – western central; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
Global abundance has not been estimated for Cuvier’s beaked whales, but abundance has been estimated for several study areas. Wade and Gerrodette (1993) estimated an abundance of about 20,000 (CV=27%) Cuvier’s beaked whales in the eastern tropical Pacific, but a re-analysis of the same data increased that to about 80,000 after accounting for diving animals that were missed (Ferguson and Barlow 2001). Other dive-corrected estimates of Cuvier’s beaked whale abundance include 1,884 (CV=68%) off the U.S. west coast (Barlow 2003) and 15,242 (CV=143%) in Hawaiian waters (Barlow 2006). Cuvier’s beaked whales are undoubtedly among the most common and abundant of all the beaked whales, and worldwide abundance is likely to be well over 100,000. There is no information on trends in the global abundance of this species.
This is the only widely-distributed beaked whale species for which a global assessment of genetic diversity has been conducted. The results of this study suggest that there is probably little movement of Cuvier’s beaked whales among different ocean basins, and that there may even be a distinct subpopulation in the Mediterranean Sea (Dalebout et al. 2005).
|Habitat and Ecology:||
Although Cuvier’s beaked whales can be found nearly anywhere in deep (>200 m) waters, they seem to prefer waters near the continental slope, especially those with a steep sea bottom. Off Japan, whaling records indicate that Z. cavirostris is most commonly found in waters deeper than 1,000 m (Heyning 1989). The species is known around many oceanic islands, and in some enclosed seas. It is rarely found close to mainland shores, except in submarine canyons or in areas where the continental shelf is narrow and coastal waters are deep (Heyning 1989, 2002) and is mostly a pelagic species that appears to be confined by the 10°C isotherm and the 1,000 m bathymetric contour (Houston 1991; Robineau and di Natale 1995).
Cuvier's beaked whales, like all beaked whales, appear to prefer deep waters for feeding. Dives of up to 40 minutes have been documented. Although few stomach contents have been examined, they appear to feed mostly on deep-sea squid, but also sometimes take fish and some crustaceans (MacLeod et al. 2003). They apparently feed both near the bottom and in the water column. As with other beaked whales, suction appears to be used to draw prey items into the mouth at close range (Heyning and Mead 1996).
|Use and Trade:||It is hunted at a low, and largely opportunistic, level.|
There is good evidence of large-scale reductions in many predatory fish populations (e.g., Baum et al. 2003, 2005; Sibert et al. 2006; Polacheck 2006) and over-fishing and collapse of several important “prey” fish stocks world-wide (e.g., Jackson et al. 2001). The effects of such fish population reductions and subsequent ecosystem changes on world-wide populations these whales are unknown but could result in population declines.
Never the main target of commercial whalers, Cuvier’s beaked whales have sometimes been taken as bycatch in other direct fisheries, such as those in the Caribbean islands, Indonesia, Taiwan, Peru, and Chile (Heyning 1989; Jefferson et al. 1993). In the Japanese Berardius fishery, Z. cavirostris have been taken on an opportunistic basis, with catches varying from 3 to 35 animals taken yearly (Omura and Kimura 1955). Although the Berardius fishery still continues, there have been no direct takes of Z. cavirostris in recent years (Nishiwaki and Oguro 1972).
Mignucci-Giannoni et al. (1999) conducted an assessment of cetacean strandings in waters off Puerto Rico, the United States and the British Virgin Islands to identify the factors associated with reported mortality events between 1867 and 1995. The most common human-related cause categories observed were entanglement and accidental captures, followed by animals being shot or speared.
Bycatch of Cuvier’s beaked whales has been reported in several fisheries. Julian and Beeson (1998) report a mortality of 22-44 individuals per year in the California/Oregon drift gillnet fishery from 1992 to 1995. Mora Pinto et al. (1995) report on bycatches from Colombian fisheries. Notarbartolo di Sciara (1990) reported on bycatch in the Italian swordfish fishery. Bycatch in the western North Atlantic is very low, with one animal reported between 1994 and 1998 (Waring et al. 2001).
Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk.
In recent years, there has been increasing concern that loud underwater sounds, such as active sonar and seismic operations, may be harmful to beaked whales (Malakoff 2002). The use of active sonar from military vessels has been implicated in a number of mass strandings of Cuvier’s beaked whales, including in the Mediterranean Sea during 1996 (Frantzis 1998), the Bahamas during 2000 (Balcomb and Claridge 2001), the Madeira Islands in 2000 (Frietas 2004) and the Canary Islands in 2002 (Jepson et al. 2003). Mass strandings of Cuvier’s beaked whales in Japan also appear to be correlated with locations of naval exercises (Brownell et al. 2006). A stranding of two Cuvier’s beaked whales in the Gulf of California was closely correlated with a seismic survey (Malakoff 2002).
Predicted impacts of global climate change on the marine environment may affect this species of whale, although the nature of impacts is unclear (Learmonth et al. 2006).
The species is listed in Appendix II of CITES.
In 2004, the Parties to the UNEP CMS Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS) adopted a resolution recommending that human activities introducing high-intensity noise in the marine environment be avoided in the agreement area where high concentrations of Cuvier’s beaked whales may occur. The agreement’s Scientific Committee is currently modelling Mediterranean sighting data to generate predictive Ziphius habitat maps for that purpose.
|Citation:||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. 2008. Ziphius cavirostris. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 03 July 2015.|